The Clinical Core (CC) of the Center of Excellence for Research on Complementary and Integrative Health (CERCIH) will facilitate the clinical activities of the three proposed Projects, providing support and expertise to unify all clinical aspects of our human subjects experimental designs. The CC will recruit, screen, characterize, and enroll 120 subjects with recurrent migraine headaches and 30 age- andgender-matchedhealthycontrols.MostlyusingphysicianreferralsandourResearchPatientData Registry(RPDR),thecorewillutilizeahighlyskilledandexperiencedteamtosuperviseandimplement these goals. The CC will be the central randomization point for Projects 1, 2, and 3 and provide the network and referrals to support recruitment of all subjects and ensure adherence to the common inclusion/exclusion criteria utilized for all three Projects. The CC will randomize subjects using a 2 x 2 design: Mindfulness-Based Stress Reduction (MBSR) versus Health Education Training (HET) X transcutaneousvagusnervestimulation(tVNS)comparedtoshamtVNS.TheCCwillensurethatthe MBSRandHETaredeliveredcorrectlyandadheretoprotocol.TheCCwillrecruit,trainandsupervise the MBSR group leaders who will perform all of the necessary trainings and education sessions. The CC will refine and implement the methodologies, including audiotaping and fidelity rating of training sessions, to ensure group leader protocol compliance. The CC will use accelerometer-based, ecologic momentary assessment to measure mindfulness practice dose during the study so as to ensure accurate measurement of individual subjects? level of mindfulness practice. The CC will oversee and integrate our respiratory-gated tVNS approach with MBSR and HET sessions, including the sham tVNS, where needed. The CC will ensure that devices will be available to accommodate all subjects and that the units are reliably utilized within each session. In collaboration with the biostatistics core, the CC will collect self-report measures to investigate relevant clinical correlates such as headache frequencyandintensity,daysoflostfunction,perceivedstress,andpaininterference.TheCCwillalso collect self-report data for mediation and moderation analyses, including chronic disease self-efficacy, perceived control, anxiety, depression, trait mindfulness, mindfulness practice behaviors, self- compassion, interoceptive awareness, and emotional dysregulation. While infrequent, the CC will be available to provide medical coverage and assessment for any medical or psychiatric adverse effect fromtVNSand/ormindfulness.TheCCwillmeetonceperyearwiththeDataSafetyMonitoringBoard to review and discuss any new internal or pertinent external data, as well as to monitor safety, effectiveness, and study conduct. The CC will also coordinate any necessary independent monitoring activitiesasrequired,andsuccessfullymanageonecommonIRBacrossthe3projects.